NISSAN 44140-N9500 Brake Caliper Guide Pin

The genuine NISSAN 44140-N9500 brake caliper guide pin (also known as a caliper slider pin) is a critical safety component in floating caliper brake systems. Its primary function is to ensure precise, smooth axial movement of the brake caliper relative to the brake disc during brake application. This unrestricted movement is essential for balanced, two-sided clamping of the brake pads and their proper retraction once braking force is released.

Technical Features and Specifications:

• Manufacturer: NISSAN (Genuine OEM part)
• OEM Part Number: 44140-N9500
• Alternative / OEM References: 0274N15R
• Product Type: Brake caliper guide pin / slider pin
• Material Composition: Precision-machined, hardened alloy steel engineered to withstand high temperatures and severe mechanical stress.
• Surface Treatment: Specialized anti-corrosion coating to ensure smooth travel and prevent seizing.

Function and Operation:

In a floating caliper braking system, the caliper housing slides laterally along the guide pins. When hydraulic pressure pushes the caliper piston against the inner brake pad, the reacting force pulls the caliper body along the guide pins, pressing the outer pad against the disc. Without adequate lubrication and friction-free pin movement, braking efficiency is significantly impaired.

Common Symptoms of Wear or Failure:

• Uneven Brake Pad Wear: A sticking or seized guide pin can cause one pad to remain in continuous contact with the rotor, resulting in premature wear.
• Caliper Sticking/Binding: The brake fails to release completely, leading to brake overheating, rotor warping, and increased fuel consumption.
• Vehicle Pulling During Braking: If a guide pin sticks on one side of the vehicle, it may cause the vehicle to pull to one side under braking.
• Brake Noise: Rattling, clunking, or metallic squealing sounds can occur due to excessive play or a seized caliper.

During brake system service (such as replacing brake pads), it is always recommended to inspect, clean, and lubricate the guide pins using a dedicated high-temperature silicone-based brake grease, or replace them with genuine OEM components when necessary.